bradykinin

Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

n. A biologically active polypeptide, consisting of nine amino acids, that forms from a blood plasma globulin and mediates the inflammatory response, increases vasodilation, and causes contraction of smooth muscle.

from Wiktionary, Creative Commons Attribution/Share-Alike License

n. One of the kinins, a nonapeptide that reduces blood pressure by dilating blood vessels.

from the GNU version of the Collaborative International Dictionary of English

n. a hypotensive tissue hormone (C50H73N15O11) which acts on smooth muscle, dilates peripheral vessels and increases capillary permeability. It is formed locally in injured tissue and is believed to play a role in the inflammatory process. It is a nonapeptide with the sequence: Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg.

Upon the inflation of the alveoli, the lungs release a substance called bradykinin, which causes contraction in smooth muscle and is thought to be partially responsible for contraction of the ductus arteriosus.